JPS6138069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in crawler traveling devices used in various types of traveling machines, including construction machines such as dozers and excavators.

Generally, this type of traveling device has an endless crawler wrapped between wheels that are pivotally supported at both the front and rear ends of a frame, and one of the two wheels is used as a drive wheel to drive the crawler, while the other wheel is used to move forward and backward. The crawler is made movable and is biased in the direction of tension by a hydraulic cylinder to maintain the crawler in a predetermined tension state. However, with such a configuration, if a large impact force is applied to the cylinder due to the crawler running onto a rock, etc.,
The internal pressure of the cylinder rises abnormally, causing damage to piping in the hydraulic supply system, oil leakage, etc., which in turn reduces the tensioning force of the crawler, causing the crawler to come off the track. Since ordinary hydraulic oil was used for operation, oil leakage easily occurred from the cylinder and piping system, which caused problems such as abnormal consumption of the hydraulic oil and contamination of the surrounding area. This required a complicated sealing device, resulting in high costs.

The present invention solves such problems in conventional crawler traveling devices, and the main body of the crawler tensioning cylinder device is supported by a supporting member fixed to a frame so as to be movable back and forth, and this is supported by a spring when the crawler tensioning cylinder device is moved back and forth. By applying force in the direction of tension, even if an impact force is applied to the cylinder device, the spring absorbs the impact force, thereby preventing damage to piping, oil leakage, etc.
By using grease instead of conventional hydraulic oil to operate the cylinder, oil leakage and the above-mentioned problems associated with it are prevented, and a simple sealing device can be used, reducing costs. This is intended to reduce the amount of water used.

This will be explained below using an example shown in the figure.
In FIG. 1, 1 is a track frame in a crawler traveling device, 2 and 3 are wheels mounted on both front and rear ends of the frame, 4 is an endless crawler wound between both wheels, and one wheel 2 is The other wheel 3 is a driving wheel of a crawler rotated by a hydraulic motor 5, and the other wheel 3 is attached to the frame 1.
The crawler tension wheels are movable back and forth relative to the crawler 4, and the upper and lower sides of the crawler 4 are guided and held by guide wheels 6 and 7.
Next, in FIG. 2, 8 is a cylinder device that urges the crawler tensioning wheel 3 in the tensioning direction (direction A), 9 is a support member that supports this device with respect to the frame 1, and the cylinder device 8 is attached to this member. A cylinder main body 8a at 8 is fitted and supported so as to be movable back and forth, and the main body is urged in the crawler tensioning direction via a pressing member 11 by a spring 10 whose one end is locked to the frame side. Further, the shaft supporting member 12 of the wheel 3 is connected to the piston 8b installed inside the main body. 13a and 13b are grease supply passages leading from the outside of the support member 9 to the inside of the cylinder body 8a, and the upstream grease supply passage 13a formed on the support member side and the downstream grease supply passage 13b formed on the cylinder body side are as follows: Second
As shown in Figure a, the cylinder body 8a is connected to the spring 1.
The positional relationship is such that the main body is connected when the main body is moved in the crawler tensioning direction by 0, and is interrupted when the main body is moved against the spring by its internal pressure, as shown in FIG. Further, an external pipe 14 is connected to the passage 13a on the supporting member side.
15 is a grease supply device that supplies grease into the cylinder body 8a through the pipe 14 and the passages 13a and 13b.This device has a piston 17 built into the cylinder body 16, and the chambers on both sides thereof are connected to a hydraulic oil chamber 18 and a grease supply device. The discharge chamber 19 is equipped with a return spring 20 for the piston, and a grease replenishment tank 2.
The pipe 14 is connected to the grease discharge port 19a in the discharge chamber, and the hydraulic circuit 23 for operating the hydraulic motor 5 by a pump 22 is connected to the inlet 18a of the hydraulic oil chamber. A hydraulic oil supply path 24 led from is connected thereto. Here, in the hydraulic circuit 23, 25
26 is a pressure regulating valve, 27a and 27b are check valves, and hydraulic oil is supplied to the hydraulic oil supply path 24 or grease supply device 15 during normal rotation and reverse rotation of the motor. However, a hydraulic oil supply circuit dedicated to the grease supply device may be provided separately from this circuit. Also,
In the illustrated embodiment, a replenishment tank 21 in the grease supply device 15 is equipped with a piston 21a and a spring 21b for reliably feeding grease into the discharge chamber 19.

Next, to explain its operation, FIG. 2a shows a state in which the crawler 4 is relaxed, and in this case, the cylinder body 8a is pressed by the spring 10 and the upstream side formed between the body and the support member 9 is In the grease supply device 15 in which the grease supply passages 13a and 13b on the downstream side are connected, and pressure oil is introduced from the pump 22 of the hydraulic circuit 23, the piston 17 resists the return spring 20. The grease in the discharge chamber 19 is discharged from the discharge port 19a, and this flows through the pipe 14 and the passages 13a and 13b to the cylinder body 8a.
This causes the piston 8
b is pressed in the direction A, and the wheel 3 is urged in the crawler tensioning direction via the shaft support member 12. Further, when the crawler 4 reaches a predetermined tension state, the cylinder body 8a is forced to retreat against the spring 10 due to its internal pressure, and therefore the passages 13a and 13b are blocked as shown in FIG. 2b. As a result, the supply of grease is stopped and the inside of the cylinder body is sealed, thereby maintaining the crawler in a predetermined tension state.

However, according to the above configuration, even if an impact force is applied from the crawler 4 to the cylinder device 8 in the state shown in FIG. is relaxed and absorbed, and the grease supply passages 13a, 13b
is blocked, even if the internal pressure of the cylinder body temporarily increases abnormally due to an impact, the effect will not extend from the external piping 14 to the grease supply device 15 side, thus preventing damage to the piping system. etc. are prevented. Furthermore, since the viscosity of the grease supplied to the cylinder body 8a is significantly higher than that of conventional hydraulic oil, the grease may leak from the fitting part between the body and the support member 9 or the protrusion of the piston 8b from the body. There is almost nothing to do, and as a result, as shown in the figure, the simplest O-ring 2 is used as a sealing device.
8.29 will be sufficient.

As described above, in the crawler traveling device of the present invention, the cylinder body of the cylinder device that biases the crawler tensioning wheel in the tensioning direction is supported so as to be movable back and forth with respect to the support member, and the cylinder body is supported by the spring in the crawler tensioning direction. Grease is used in place of conventional hydraulic oil for energizing and operating the cylinder device, and furthermore, each of the upstream and downstream greases is formed on the support member side and the cylinder body side, respectively, in a predetermined crawler tension state. Since the supply passage is cut off, even if a large impact force is applied from the crawler to the cylinder device due to the traveling device running aground on a rock, this will be absorbed by the spring and will reduce the durability of the machine. This not only improves performance and ride comfort, but also prevents damage to piping in the grease supply system and the resulting drop in tension, which can cause crawlers to come off the rails. This has the effect of preventing oil leakage, abnormal consumption of hydraulic oil, and contamination of the surrounding area, etc., which would otherwise occur.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of a crawler traveling device showing an embodiment of the present invention, and Fig. 2 is an enlarged vertical sectional view of the main part of the embodiment, in which figure a shows the crawler in a relaxed state, and figure b
Similarly, they each indicate a state of tension. 3...Crawler tension wheel, 4...Crawler, 8...
Cylinder device, 8a... Cylinder body, 8b... Piston, 9... Support member, 10... Spring, 13a, 13
b...Grease supply passage, 15...Grease supply device, 1
9a...Discharge port, 22...Pump.

Claims (1)

[Claims] 1 A crawler traveling device comprising a drive wheel and a crawler tensioning wheel movable back and forth supported at both ends of a frame, and an endless crawler wound between both wheels, which is fixed to the frame. A cylinder body is fitted and supported in a supporting member so as to be slidable back and forth, a piston to which the crawler tensioning wheel is connected is fitted inside the cylinder body, and the cylinder body is moved in the tensioning direction of the crawler by means of a spring. The support member is provided with an upstream grease supply passage connected to the grease supply device, and the cylinder body is connected to the upstream grease supply passage so that there is no flow from the grease supply device into the cylinder body. By introducing the pressure-fed grease, pressure is applied to the piston in the crawler tensioning direction, and when the cylinder body is moved in the anti-crawler tensioning direction against the spring due to the pressure, the pressure is applied to the piston from the upstream grease supply passage. A crawler traveling device characterized by providing a downstream grease supply passage that is blocked.